The Illumina Genome Analyzer IIx (GA II) is a robust, versatile "Next Generation" DNA sequencing instrument with a wide range of validated applications, including whole genome DNA sequencing, transcriptome resequencing, whole-genome methylation profiling, digital gene expression, ChIP-Seq, among others. With more than 200 publications based on data generated using the platform, the GA II has become the most widely used of the current generation of sequencing platforms and the dominant instrument at leading genome centers. In support of a number of ongoing projects at Dana-Farber that required DNA sequencing and sequence analysis, John Quackenbush recently received a grant from a local charity that allow for a long-term lease/purchase agreement for a GA II;the instrument was installed in the second week of March of 2009. Here we are seeking the funds necessary to complete the purchase of that instrument and in doing so to support the projects that depend upon it.